Frame structure of saddle riding type vehicle

ABSTRACT

A frame structure of a saddle riding type vehicle, the frame structure includes a main frame body configured to support the power unit and the front wheel suspension device; and a steering post configured to support a steering shaft at above of the main frame body, wherein the steering post includes a shaft holder configured to rotatably support the steering shaft, and a plurality of column members that extend downward from the shaft holder and that are fixed to the main frame body, and wherein the steering post is detachable with respect to the main frame body.

CROSS-REFERENCE TO RELATED APPLICATION

Priority is claimed on Japanese Patent Application No. 2017-065877, filed Mar. 29, 2017, the content of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention relates to a frame structure of a saddle riding type vehicle.

Description of Related Art

In the related art, in a saddle riding type vehicle, a configuration in which a front wheel suspension device is arranged in front of a power unit and a height of the front wheel suspension device is suppressed is known (for example, see Japanese Unexamined Patent Application, First Publication No. 2016-147539).

SUMMARY OF THE INVENTION

In the above mentioned Japanese Unexamined Patent Application, First Publication No. 2016-147539, a frame body of the front wheel suspension device is directly fixed to a front section of the power unit. Conversely, it is possible to consider providing a main frame body for supporting the power unit and to support suspension devices of the front and rear wheels at this main frame body. In this case, even the height of the main frame body is suppressed like the front wheel suspension device, since the steering handle which the driver operates is located above of the main frame body, and therefore, a structure for supporting a steering shaft which is connected to the steering handle will be necessary.

An aspect of the present invention is to provide a frame structure of a saddle riding type vehicle that can efficiently support the steering shaft arranged at above the main frame body supporting the front wheel suspension device.

A frame structure of a saddle riding type vehicle according to the present invention employs the following configuration.

(1) A frame structure of a saddle riding type vehicle according to an aspect of the present invention is a frame structure of a saddle riding type vehicle in which a front wheel suspension device is arranged in front of a power unit, the frame structure includes a main frame body configured to support the power unit and the front wheel suspension device; and a steering post configured to support a steering shaft at above of the main frame body, wherein the steering post includes a rotating support member configured to rotatably support the steering shaft, and a plurality of column members that extend downward from the rotating support member and that are fixed to the main frame body, and wherein the steering post is detachable with respect to the main frame body.

According to the configuration of above mentioned (1), by providing a steering post, which supports the steering shaft, i.e., steering handle, detachable with respect to the main frame body for supporting the power unit and the front wheel suspension device, it is possible to easily consist a plurality of vehicle types that have different handle positions by sharing the main frame body and by only replacing the steering post. In addition, by supporting the rotating support member of the steering post with the plurality of column members, it is possible to suppress the weight of the steering post, and to appropriately support the components at the upper part of the vehicle body with the plurality of column member, and the number of components can be reduced compared to a case in which stays and the like are provided to every components.

(2) In the aspect of above mentioned (1), the rotating support member may be configured to support the steering shaft via a bearing that can be automatically centered.

According to the configuration of above mentioned (2), even in a rotating support member supported by a plurality of column members, it is possible to absorb the deviation of a shaft center with respect to the steering shaft by a bearing that can be automatically centered and to make the rotation of the steering shaft satisfactory.

(3) In the aspect of above mentioned (1) or (2), a vehicle functional component may be arranged in a space surrounded with the plurality of column members.

According to the configuration of above mentioned (3), by arranging the vehicle functional components such as air cleaner box and the like that requires high volume in a space formed by the steering post, it is possible to cover the size of the component with efficiently using a limited components arrangement space in the saddle riding type vehicle.

(4) In the aspect of any one of above mentioned (1) to (3), a front column member that locates in front of the steering post among the plurality of column members may be arranged at a position where the front column member overlaps with an axis of the rotating support member in a side view or a position which is rearward than the axis.

According to the configuration of above mentioned (4), since the steering shaft does not come inside the space surrounded by the plurality of column members, it is possible to secure a space in which the vehicle functional components are arranged without narrowing the space formed by the steering post.

(5) In the aspect of any one of above mentioned (1) to (4), each of a lower end portions of the plurality of column members may be fixed to the main frame body, the lower end portion of the front column member, which is located in front of the steering post among the plurality of column members, may be disposed in front of a vertical line dropping from a center of the rotating support member in a side view, and the lower end portion of the rear column member, which is located in rear of the steering post among the plurality of column members, may be disposed in rear of the vertical line in the side view.

According to the configuration of above mentioned (5), it is possible to support the load applied to the rotating support member with the front column member and the rear column member, that are extending so as to be broaden towards the bottom in forward and rearward, respectively, in a well-balanced manner and to reduce a load with respect to the fixing points of the front and rear column members and the main frame body, and therefore, light weighting of the steering post can be achieved.

According to the aspect of the present invention, it is possible to provide a frame structure of a saddle riding type vehicle that can efficiently support the steering shaft arranged at above the main frame body supporting the front wheel suspension device.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view seen from the front side of a vehicle body front section of a saddle riding vehicle according to an embodiment.

FIG. 2 is a left side view of the vehicle body front section of the saddle riding vehicle.

FIG. 3 is a front view of the vehicle body front section of the saddle riding vehicle.

FIG. 4 is a plan view of the vehicle body front section of the saddle riding vehicle.

FIG. 5 is a perspective view seen from the back side of the vehicle body front section of the saddle riding vehicle.

FIG. 6 is a left side view of surroundings of a steering post, a rocking lock mechanism and a lock operation lever of the saddle riding vehicle.

FIG. 7 is a front view of surroundings of the steering post, the rocking lock mechanism and the lock operation lever of the saddle riding vehicle.

FIG. 8 is a perspective view of surroundings of the steering post of the saddle riding vehicle.

FIG. 9 is a cross-sectional view of a lateral center of the steering post of the saddle riding vehicle.

DETAILED DESCRIPTION OF THE INVENTION

Hereinafter, an embodiment of the present invention will be described on the basis of the accompanying drawings. Further, directions of forward, rearward, leftward, rightward, and the like shown below are the same as directions in a vehicle described below unless the context clearly indicates otherwise. In addition, in appropriate places in the drawings used in the following description, an arrow FR showing a forward direction with respect to a vehicle, an arrow LH showing a leftward direction with respect to the vehicle and an arrow UP showing an upward direction with respect to the vehicle are provided.

<Entire Vehicle>

FIG. 1 shows a vehicle body front section of a saddle riding vehicle 1 of the embodiment. The saddle riding vehicle 1 includes a pair of left and right front wheels (steered wheels) 2 installed on the vehicle body front section in lateral symmetry and a rear wheel (not shown) installed on a vehicle body rear section as a single driving wheel. The saddle riding vehicle 1 is configured as a two-front-wheeled type three-wheeled rocking vehicle that enables lateral rocking (rolling motion) of a vehicle body 1A in a state in which the left and right front wheels 2 are in contact with the ground. The saddle riding vehicle 1 of the embodiment includes a frame structure 100 that includes a main frame body 6 and a steering post 13, which will be described below.

In the following description, a configuration when the vehicle is in a state in which the left and right front wheels 2 are in contact with the ground on a horizontal road surface R, a load corresponding to a vehicle weight is applied to a two-front-wheeled suspension system 4 (to be described below) in a state of 1 G, the vehicle body 1A stands upright at a lateral rocking angle of 0 degrees, and a steered angle of the left and right front wheels 2 is an advancing straight ahead steering state of 0° will be described unless the context indicates otherwise. In the description as given below, lateral symmetry with respect to a vehicle body lateral center is formed unless the context indicates otherwise.

Referring to FIG. 2, in the saddle riding vehicle 1, a front suspension frame body 5 of the two-front-wheeled suspension system 4 is integrally coupled to a front section of a main frame body 6 disposed at a center of the vehicle body. A rear wheel suspension system (not shown) is connected to a rear section of the main frame body 6. The main frame body 6 is formed in a cradle shape that surrounds a power unit 3A of the saddle riding vehicle 1, and obtained by integrally coupling a plurality types of metal material through welding or the like. For example, the power unit 3A includes a horizontally opposed engine 3.

Referring to FIG. 5, the main frame body 6 includes a pair of left and right main frames 7 extending in a forward/rearward direction of the vehicle and bent in an inverted V shape when seen in a side view, a pair of left and right pivot frames 8 extending downward to be connected to rear sections 7 b of the left and right main frames 7, and a pair of left and right down frames 9 extending downward from front end portions of the left and right main frames 7 and then extending to be bent rearward and connected to front sides of lower sections of the left and right pivot frames 8. The main frame body 6 includes a cross frame configured to connect the left and right frame members at an appropriate place.

Referring to FIG. 1 and FIG. 6, a fuel tank 37 for the engine 3 is disposed above the left and right main frames 7. A seat 36 on which an occupant sits is disposed behind the fuel tank 37. A pair of left and right radiators 40 are disposed on left and right outer sides of front sections 7 a of the left and right main frames 7. Surroundings of the left and right radiators 40 are covered by a pair of left and right radiator shrouds 40 a. The left and right radiator shrouds 40 a extends to a front side of the vehicle beyond the fuel tank 37 and front end positions of the left and right main frames 7.

Referring to FIG. 2 to FIG. 5, a steering post 13 configured to support an upper section of a steering shaft 12 is attached to a front upper section of the main frame body 6. A bar type steering handle 11 is attached to an upper end portion of the steering shaft 12 via a handle post 11 a above the steering post 13. A lower section of the steering shaft 12 is pivotably supported by a rear section of the front suspension frame body 5. A line CL in the drawings designates a lateral center of the vehicle body 1A (a vehicle body lateral center).

A central axis (a steering axis) C1 of the steering shaft 12 is disposed on a vehicle body lateral center CL. The steering axis C1 is inclined such that an upper side in a vertical direction is disposed on a rear side when seen in a side view. The steering shaft 12 is disposed to overlap the front end portions of the main frames 7 when seen in a side view. While the steering shaft 12 integrally extends from the handle post 11 a into the rear section of the front suspension frame body 5, the steering shaft 12 is not limited to an integrated member and may be configured to integrally pivot even if the steering shaft 12 is divided in the middle.

The steering post 13 is provided in a state in which a cylindrical shaft holder 14 (rotating support member) through which the steering shaft 12 is inserted is supported by a pair of left and right front columns 15 (column member, front column member) and a pair of left and right rear columns 16 (column member, rear column member). The shaft holder 14 is disposed in a direction in which the rear sections 7 b inclined forward and upward in the left and right main frames 7 is extended when seen in a side view. The front sections 7 a of the left and right main frames 7 are inclined forward and downward, and a height of the main frame body 6 is restricted.

Referring to FIG. 1, FIG. 6 and FIG. 7, an upper rear portion and side portions of the steering post 13 are covered by the front section of the fuel tank 37 and the left and right radiator shrouds 40 a. A front side of the steering post 13 is covered by a front cover 38. A headlight 38 a is disposed on the upper section of the front cover 38. A meter device 39 is supported by the handle post 11 a on an upper rear side of the front cover 38. A brake lever 11 b is disposed in front of a right grip of the steering handle 11, and a clutch lever 11 c is disposed in front of a left grip of the steering handle 11. The brake lever 11 b is at least one operator for front and rear wheel brakes, and the clutch lever 11 c is an operator for a transmission clutch between the engine 3 and a gearbox (not shown) in the power unit 3A. A front lower cover 20 extending in the upward/downward direction is attached to the front end portion of the front suspension frame body 5.

Referring to FIG. 2 to FIG. 5, the two-front-wheeled suspension system 4 has an aspect of a double wishbone configured to independently suspend the left and right front wheels 2 on both sides of the front suspension frame body 5. Suspension components such as the front suspension frame body 5 of the two-front-wheeled suspension system 4, left and right upper arms 21, lower arms 23, cushion units 30, and so on, are disposed generally below extension lines 7 a 1′ of upper surfaces 7 a 1 of the front sections 7 a of the left and right main frames 7 when seen in a side view. Accordingly, a height of the suspension components of the two-front-wheeled suspension system 4 is restricted, and such disposition contributes to lowering of a center of gravity of the saddle riding vehicle 1.

Front end portions of the left and right main frames 7 are bent inward in the vehicle width direction and are integrally joined to each other. The front suspension frame body 5 is fastened and fixed to the front end portions of the left and right main frames 7 and the left and right down frames 9. A rear wheel suspension system (not shown) is connected to the rear section of the main frame body 6 including the left and right pivot frames 8.

<Front-Two-Wheeled Suspension System>

In the two-front-wheeled suspension system 4, in a state in which the left and right front wheels 2 are in contact with the ground, the vehicle body 1A including the main frame body 6, the power unit 3A, the front suspension frame body 5, and so on, can be laterally rocked, and the left and right front wheels 2 can be similarly laterally rocked according to the lateral rocking of the vehicle body 1A. On the other hand, the two-front-wheeled suspension system 4 enables the left and right front wheels 2 to alternately vertically move with respect to the vehicle body 1A.

Referring to FIG. 2 to FIG. 5, the front suspension frame body 5 extends in front of the main frame body 6 at a center in the vehicle width direction. Outer link members 25 are supported on left and right sides of the front suspension frame body 5 via the upper arms 21 and the lower arms 23. Left and right knuckle members 26 and the left and right front wheels 2 are steerably supported by the left and right outer link members 25.

The inner end portions disposed at centers of the left and right upper arms 21 in the vehicle width direction are vertically rockably supported by the upper section of the front suspension frame body 5 via an upper rocking shaft 22 extending generally in a forward/rearward direction. The inner end portions disposed at the centers of the left and right lower arms 23 in the vehicle width direction are vertically rockably supported by the lower section of the front suspension frame body 5 via a lower rocking shaft 24 parallel to the upper rocking shaft 22. Axes C2 and C3 of the upper and lower rocking shafts 22 and 24 are disposed in a posture raised at the front in which an inclination angle in a horizontal direction is reduced with respect to a direction perpendicular to an axis C1 of the steering shaft 12.

The upper end portions of the left and right outer link members 25 are rockably supported by the outer end portions of the left and right upper arms 21 via upper outer rocking shafts 25 a parallel to the upper and lower rocking shafts 22 and 24. The lower end portions of the left and right outer link members 25 are rockably supported by the outer end portions of the left and right lower arms 23 via lower outer rocking shafts 25 b parallel to the upper and lower rocking shafts 22 and 24.

When seen in the axial direction of the upper and lower rocking shafts 22 and 24, the left and right upper arms 21, the left and right lower arms 23 and the left and right outer link members 25 are disposed in a parallel link shape on left and right sides of the vehicle body. Accordingly, when the left and right upper arms 21 and the left and right lower arms 23 vertically rock, the left and right outer link members 25 vertically move substantially parallel to each other, and the left and right knuckle members 26 and the left and right front wheels 2 vertically move substantially parallel to each other together with the left and right outer link members 25. The upper and lower rocking shafts 22 and 24 are rocking shafts of the vehicle body 1A.

Here, a steering link mechanism 12 c is connected to a lower end portion of the steering shaft 12. The left and right knuckle members 26 are connected to the steering link mechanism 12 c via left and right tie rods 27. The left and right front wheels 2 are rotatably and axially supported by the left and right knuckle members 26. Pivotal movement of the steering handle 11 and steering of the left and right front wheels 2 are linked via the steering shaft 12, the steering link mechanism 12 c, the left and right tie rods 27 and the left and right knuckle members 26.

Referring to FIG. 2 to FIG. 5, when seen in the axial direction of the upper and lower rocking shafts 22 and 24, the left and right tie rods 27 are installed to be substantially parallel to and have substantially the same length as those of the left and right upper arms 21 and the left and right lower arms 23. That is, when seen in the axial direction of the upper and lower rocking shafts 22 and 24, the left and right tie rods 27, the left and right upper arms 21 and the left and right lower arms 23 are disposed in a parallel link shape on left and right sides of the vehicle body. Accordingly, when the left and right upper arms 21 and the left and right lower arms 23 vertically lock, the left and right tie rods 27 vertically rock substantially parallel to the left and right upper arms 21 and the left and right lower arms 23, and an influence on a steering angle of the left and right front wheels 2 is minimized.

The left and right cushion units 30 configured to receive loads to the left and right front wheels 2 extend generally in the upward/downward direction at above the rear sections of the left and right lower arms 23. The left and right cushion units 30 are inclined such that upper sides thereof in the vertical direction are disposed on a rear side, and are disposed to extend to be perpendicular to the upper and lower rocking shafts 22 and 24 when seen in a side view. The left and right cushion units 30 are disposed to extend substantially vertically when seen in a front view.

The left and right cushion units 30 have lower end portions thereof connected to the left and right lower arms 23, and upper end portions thereof connected to left and right end portions of cushion support arms 29, respectively. The left and right central portions of the cushion support arms 29 are rockably supported by the front suspension frame body 5 via rocking shafts 29 a parallel to the upper and lower rocking shafts 22 and 24. An actuator 41 configured to control an inclination angle of the vehicle body 1A is connected to the cushion support arms 29 via link members 44 (see FIG. 6 and FIG. 7).

The cushion support arms 29 integrally have left and right arm sections 29 b. The left and right arm sections 29 b are disposed in a parallel link form on left and right sides of the vehicle body together with the left and right lower arms 23 and the left and right cushion units 30 when seen in the axial direction of the upper and lower rocking shafts 22 and 24. Accordingly, when the left and right arm sections 29 b and the left and right lower arms 23 vertically rock, the left and right cushion units 30 vertically rock substantially parallel thereto.

The outer link members 25 extend generally in the upward/downward direction, and support knuckle members 26 on the outer sides of the lower sections thereof. The knuckle members 26 steerably support steering axles (king pin shafts) substantially parallel to the steering shaft 12 when seen in a side view. Hubs (not shown) of the front wheels 2 are rotatably supported by the knuckle members 26 via axles 28. Wheels 2 a of the front wheels 2 are fastened and fixed to the hubs by a plurality of fastening sections 2 b. Front wheel brakes (not shown) are provided inside the wheels 2 a.

Central axes (king pin axes) C9 of the left and right steering axles are disposed on vertical lines offset equidistantly from the vehicle body lateral center CL to left and right sides when seen in a front view. The king pin axes C9 are disposed to be inclined such that upper sides are disposed on rear sides when seen in a side view. An intersection T1′ of a downward extension portion of a king pin axis C9 with the road surface R when seen in the side view is disposed in front of a ground-contact point T1 vertically below an axle center C5 of the front wheels 2 to generate a trail. An inclination angle of the king pin axes C9 in the vertical direction is a caster angle when seen in a side view. The axles 28 of the front wheels 2 are offset toward front sides of the king pin axes C9 when seen in a side view.

<Rocking Lock Mechanism>

Referring to FIG. 6 and FIG. 7, a lock plate 31 having an arc-shaped section 31 a about the rocking shafts 29 a of the cushion support arms 29 is fixed to upper sections of the cushion support arms 29. The lock plate 31 is formed in a plate shape perpendicular to the axial direction of the upper and lower rocking shafts 22 and 24. The lock plate 31 has left and right leg sections 31 b extending downward from both of left and right end portions of the arc-shaped section 31 a curved to protrude upward. The lower end portions of the left and right leg sections 31 b are fastened and fixed to the upper section of the left and right arm sections 29 b of the cushion support arms 29, respectively.

A lock caliper 32 that can clamp the arc-shaped section 31 a in a thickness direction is disposed on the upper end position of the arc-shaped section 31 a. The lock caliper 32 is fastened to and supported by the steering post 13 via a caliper stay 33 in the leftward/rightward direction. The lock plate 31 and the lock caliper 32 constitute the rocking lock mechanism 32A configured to lock the lateral rocking of the vehicle body 1A.

When the vehicle body 1A is in an upright state in which the lateral rocking angle is 0 degrees, the lock caliper 32 is disposed on the upper end position of the arc-shaped section 31 a. When the lock caliper 32 clamps the lock plate 31 in this state, the lateral rocking of the vehicle body 1A is locked in the upright state.

When the vehicle body 1A is laterally rocked, while the lock caliper 32 is laterally rocked together with the vehicle body 1A, the lock plate 31 moves parallel to the cushion support arms 29 in a horizontal posture. The lock caliper 32 relatively rocks with respect to the lock plate 31 along the arc-shaped section 31 a. When the lock caliper 32 clamps the lock plate 31 in this state, the lateral rocking of the vehicle body 1A is locked at an arbitrary rocking angle. In this case, the vehicle body 1A can be raised in the upright state even on an inclined surface.

Referring to FIG. 1, FIG. 6 and FIG. 7, for example, the lock operation mechanism 34 configured to perform a lock operation and a lock release operation of the rocking lock mechanism 32A is disposed on the left side of the vehicle body front section. The lock operation mechanism 34 is disposed close to a rear upper side of the lock caliper 32 when seen in a side view. The lock operation mechanism 34 includes a base member 34 a fixed to the steering post 13, and a lock operation lever 34 b rockably supported by the base member 34 a via a rocking shaft 34 c in the vehicle width direction.

A cable locking member 34 d is integrally rockably connected to the lock operation lever 34 b. One end of an operation cable 35 is locked to the cable locking member 34 d. The other end of the operation cable 35 is locked to an actuating arm (not shown) of the lock caliper 32. Although the lock caliper 32 is biased to a side on which the internal mechanism releases the clamp of the lock plate 31, when the operation cable 35 is pulled, the lock caliper 32 is operated to clamp the lock plate 31 against the biasing force.

The lock operation lever 34 b shown by a solid line in FIG. 6 shows a state of an initial position at which a clamping operation of the lock caliper 32 is released without pulling the operation cable 35. The lock operation lever 34 b shown by a dotted-dashed line in FIG. 6 shows a state of an operation position at which the lock caliper 32 is clamped by pulling the operation cable 35.

For example, the lock operation lever 34 b pulls the operation cable 35 and clamps (locks) the lock caliper 32 when an operation of pivoting upward and rearward a gripping section 34 e that is an operation input section (a lock operation) is performed from the state of the initial position. Here, the lateral rocking of the vehicle body 1A is locked (restrained). The lock operation lever 34 b releases the clamping operation of the lock caliper 32 (a lock release action) with a termination of pulling the operation cable 35 when an operation of pivoting the gripping section 34 e downward and forward (an operation of returning the gripping section 34 e to the initial position, a lock release operation) is performed by a lock operation from the state of the operation position. Here, the lock of the lateral rocking of the vehicle body 1A is released.

Since both of the lock operation lever 34 b and the lock caliper 32 are supported by the steering post 13 of the vehicle body 1A such that a relative position therebetween is not varied, a degree of routing freedom of the operation cable 35 is high. That is, in the embodiment, in comparison with the case in which the lock operation lever 34 b is supported by the steering handle 11 or the like and the relative position is varied, there is no need to consider a surplus length of the operation cable 35 according to the variation of the relative position. Further, the lock operation lever 34 b and the lock caliper 32 may be linked via a link mechanism, a cam mechanism, or the like, in addition to the operation cable 35.

The gripping section 34 e of the lock operation lever 34 b is disposed in front of the shaft holder 14 (in front of the axis C1 of the steering shaft 12) and disposed behind the headlight 38 a at both of the initial position and operation position. At least a portion of the gripping section 34 e is disposed above the shaft holder 14 in the upward/downward direction at both of the initial position and the pivot position. Since the gripping section 34 e is disposed in front of the rear end of the shaft holder 14 even upon a maximum pivotal movement, interference of the gripping section 34 e with another member or an occupant during driving is suppressed.

The gripping section 34 e of the lock operation lever 34 b is disposed between the front end portion of the fuel tank 37 and the rear end portion of the front cover 38. The lock operation mechanism 34 is covered by a radiator shroud 40 a from the outside in the vehicle width direction except for surroundings of the gripping section 34 e of the lock operation lever 34 b. Since the gripping section 34 e of the lock operation lever 34 b is disposed in front of the fuel tank 37 gripped by an occupant's knees and disposed to be separated forward and downward from the steering handle 11 while being disposed at a position where the gripping section 34 e is easily seen from the occupant and easily operated, an unintentional contact of the occupant with the lock operation lever 34 b is suppressed.

<Actuator>

Referring to FIG. 6 and FIG. 7, the actuator 41 includes a bottomed cylindrical housing 42 parallel to the upper and lower rocking shafts 22 and 24, and a rotating drive shaft 41 a coaxial with the housing 42. The actuator 41 is an electric motor or a fluidic device configured to generate a torque around a central axis C7 in the rotating drive shaft 41 a. A motor 42 a (a rotating electric machine) including a stator and a rotor is accommodated in the housing 42. Rocking arms 43 protruding toward both of left and right sides and configured to rock around the axis C7 are installed on the rear section of the actuator 41. The rocking arms 43 are connected to the rotating drive shaft 41 a protruding toward a rear side of the housing 42 via a connecting apparatus 45. The rocking arms 43 are connected to the left and right arm sections 29 b of the cushion support arms 29 via the link members 44 extending in the upward/downward direction. The rocking arms 43, the link members 44 and the cushion support arms 29 are disposed in a parallel link shape when seen in the axial direction of the upper and lower rocking shafts 22 and 24.

A lower side of the rear end portion of the housing 42 of the actuator 41 is fixed to an actuator support section 5 a of the front suspension frame body 5. A cowl stay 5 b configured to support the front cover 38 or the like is bridged between the rear upper end portion of the housing 42 of the actuator 41 and the front end portion of the shaft holder 14 of the steering post 13.

The connecting apparatus 45 configured to connect the rocking arms 43 and the rotating drive shaft 41 a is installed on the rear end portion of the actuator 41. The connecting apparatus 45 is disposed to enter the inner circumferential region of the lock plate 31 of the rocking lock mechanism 32A together with the rotating drive shaft 41 a protruding rearward from the housing 42.

The connecting apparatus 45 accommodates a load sensor configured to detect a load (a torque) transmitted between the rocking arms 43 and the rotating drive shaft 41 a. That is, the connecting apparatus 45 functions as a torque detecting sensor configured to detect a transmission torque between the rocking arms 43 and the rotating drive shaft 41 a. The rotating drive shaft 41 a of the actuator 41 protrudes rearward from the vehicle body through the inner circumferential region of the lock plate 31 and is connected to the load sensor. A detected value of the load is input to an electronic control unit (ECU) 46 serving as a control unit configured to control an actuation of the actuator 41. The ECU 46 controls driving of the actuator 41 on the basis of a detection result of the connecting apparatus 45, a vehicle speed, an inclination of the vehicle, an operation amount of a rider, or the like.

A load around the central axis C7 generated between the rocking arms 43 and the rotating drive shaft 41 a is generated according to an operation resistance (a torque) of the actuator 41 when the cushion support arms 29 are to rock with respect to the actuator 41 supported at the vehicle body 1A side. That is, a load around the central axis C7 is generated between the rocking arms 43 and the rotating drive shaft 41 a upon lateral rocking of the vehicle body 1A according to the operation resistance of the actuator 41. The ECU 46 controls driving of the actuator 41 according to the detected value of the load. The ECU 46 controls the actuator 41 such that at least a load input from the rocking arms 43 to the rotating drive shaft 41 a, i.e., a load input from the cushion support arms 29 to the actuator 41 among the load transmitted between the rocking arms 43 and the rotating drive shaft 41 a is increased or decreased. A rocking center (the axis C7) of the rocking arms 43 of the actuator 41 and a rocking center (an axis C8) of the cushion support arms 29 are parallel to each other, and an interlocking mechanism of those is simplified.

The ECU 46 detects a moment in a falling direction and a raising direction applied to the vehicle body 1A according to, for example, a detected value of an inertial sensor or a vehicle speed sensor installed on the vehicle body 1A and controls the driving of the actuator 41 such that the moment is not excessively increased. Accordingly, lateral rocking of the vehicle body 1A with respect to the driving of the occupant is assisted or suppressed, and a light rolling motion and balancing easiness are compatible.

Further, for example, the ECU 46 controls driving of the actuator 41 such that a resistance against the rocking of the vehicle body 1A is increased when the saddle riding vehicle 1 is in a stop state or a low vehicle speed state, and controls driving of the actuator 41 such that a resistance with respect to the rocking of the vehicle body 1A is decreased when the saddle riding vehicle 1 is in a middle or high vehicle speed state.

<Steering Post>

Referring to FIG. 2 and FIG. 8, the steering post 13 is formed separately from the main frame body 6 and attached to the upper surfaces 7 a 1 of the front sections 7 a of the left and right main frames 7 of the main frame body 6. The steering post 13 is obtained integrally coupling a plurality of metal members through welding, fastening, or the like. The steering post 13 integrally has the plurality of columns 15 and 16 and the shaft holder 14 supported by the upper end portions of the plurality of columns 15 and 16. The columns 15 and 16 are formed in a pipe shape, protrude upward from the upper surfaces 7 a 1 of the front sections 7 a of the left and right main frames 7, and are set to intersect each other at the outer circumference of the cylindrical shaft holder 14 to support the shaft holder 14. The steering post 13 can achieve reduction in weight by lowering strength and rigidity because a load from the two-front-wheeled suspension system 4 and rear wheel suspension system is not input. As the steering post 13 disposed above the main frame body 6 is reduced in weight, further lowering of a center of gravity can be achieved.

The columns 15 and 16 are constituted by the pair of left and right front columns 15 and the pair of left and right rear columns 16. A pair of left and right gusset pipes 17 is bridged between the upper sections of the left and right front and rear columns 15 and 16. A distance between the left and right front columns 15 is smaller than a distance between the left and right rear columns 16, and corresponds to that the front sections 7 a of the left and right main frames 7 are formed to approach each other as they go forward. The front columns 15 are disposed with an inclination closer to a vertical direction than that of the steering shaft 12 (and the shaft holder 14) when seen in the side view. That is, when seen in the side view, an angle of the front columns 15 with respect to the vertical direction is smaller than angle of the steering shaft 12 (and the shaft holder 14) with respect to the vertical direction. The front columns 15 overlap the position in the forward/rearward direction with the axis C1 of the steering shaft 12 (that is an axis of the shaft holder 14). Accordingly, the steering shaft 12 does not enter a space K surrounded by the front and rear columns 15 and 16. Further, the front columns 15 may be disposed to be positioned behind the axis C1 of the steering shaft 12.

Lower end portions 15 a and 16 a of the front and rear columns 15 and 16 are fastened and fixed to fastening sections 7 a 2 protruding from the upper surfaces 7 a 1 of the front sections 7 a of the left and right main frames 7 by fastening bolts inserted therethrough from the outside in the vehicle width direction. That is, the steering post 13 is detachably attached to the main frame body 6. At least fastened positions of the lower end portions 15 a of the front columns 15 are disposed in front of the vertical line VL dropping from a center of the shaft holder 14 (a center of a width in the axial direction on the axis C1) when seen in the side view, and at least fastened positions of lower end portions 16 a of the rear columns 16 are disposed behind the vertical line VL when seen in the side view. The lower end portions 15 a of the front columns 15 are disposed at left and right outer sides further than the vehicle body lateral center CL, and the lower end portions 16 a of the rear columns 16 are disposed at left and right outer sides further than the vehicle body lateral center CL. Accordingly, the plurality of columns 15 and 16 extend downward from the shaft holder 14 so as to be broaden towards the bottom, and the shaft holder 14 can be supported at front, rear, left and right sides with good balance.

An air cleaner box 19 for engine intake is disposed in the space K inside the steering post 13. Since the steering shaft 12 is not disposed in the space K inside the steering post 13, presence of the steering shaft 12 does not exert an influence on a capacity of the air cleaner box 19. Accordingly, the capacity of the air cleaner box 19 can be increased as possible while disposing the air cleaner box 19 inside the steering post 13. Since the steering post 13 is detachable, assemblability or maintenance of the air cleaner box 19 is secured.

Referring to FIG. 9, the shaft holder 14 supports the steering shaft 12 via a bearing 18 that can be automatically centered. The bearing 18 is a ball bearing, a trajectory surface 18 a 1 of an outer ring 18 a is a spherical surface, and a center of the spherical surface coincides with a center of the bearing 18. The center of the bearing 18 is a point which is at a center of the outer ring 18 a within the width in the axial direction and which is on the axis C1. An inner ring 18 b has two rows of trajectory grooves 18 b 1, and a plurality of bearing balls 18 c are rolled along each of the trajectory grooves 18 b 1. The inner ring 18 b, the bearing balls 18 c and a cage (not shown) configured to hold the bearing balls 18 c are pivotable while being inclined with respect to the outer ring 18 a within a prescribed angle.

The outer ring 18 a is fixed and held by the inner circumference of the shaft holder 14, and the inner ring 18 b is fixed and held by the outer circumference of the steering shaft 12. Even when a deviation of a shaft center occurs between the shaft holder 14 and the steering shaft 12 in the configuration, the deviation of the shaft center of the outer and inner rings 18 a and 18 b is automatically adjusted. In particular, the deviation of the shaft center between the shaft holder 14 and the steering shaft 12 can be absorbed even using the steering post 13 configured to support the shaft holder 14 in the plurality of columns 15 and 16. In addition, it is also effective for the deviation of the shaft center due to the fact that the steering post 13 is detachable. A collar 14 a is interposed between the inner ring 18 b and the handle post 11 a, and an umbrella part 14 a 1 configured to cover an upper end opening of the shaft holder 14 is formed on an outer circumference of the collar 14 a. A dust seal section 14 b configured to prevent intrusion of water or foreign substances from an opening of the lower section of the shaft holder 14 is installed on the lower section inner circumference of the shaft holder 14 below the bearing 18.

Referring to FIG. 6 and FIG. 7, the lock caliper 32 is attached to the front columns 15 via the caliper stay 33. The caliper stay 33 is constituted by a belt-shaped steel member extending in the leftward/rightward direction, and bent such that left and right side portions thereof are displaced rearward with respect to left and right central portions. The lock caliper 32 is fastened and fixed to the left and right central portions of the caliper stay 33, and the left and right end portions of the caliper stay 33 are fastened and fixed to the front columns 15. The lock caliper 32 is fastened to the left and right central portions of the caliper stay 33 by fastening bolts inserted therethrough from a front side thereof, and the left and right end portions of the caliper stay 33 are fastened to the front columns 15 by fastening bolts inserted therethrough from the outside in the vehicle width direction.

While an operation of fastening the lock caliper 32 from the front side of the vehicle is interfered with the actuator 41, an operation of fastening a small assembly of the lock caliper 32 and the caliper stay 33 to the front columns 15 from the outside in the vehicle width direction is easily performed because the caliper stay 33 and fastening sections a15 b of the front columns 15 are exposed to the outside in the vehicle width direction. Accordingly, attachment workability of the lock caliper 32 can be improved.

As described above, the embodiment provides the frame structure of a saddle riding type vehicle 1 in which a front wheel suspension device 4 is arranged in front of a power unit 3A, the frame structure 100 includes a main frame body 6 configured to support the power unit 3A and the front wheel suspension device 4; and a steering post 13 configured to support a steering shaft 12 at above of the main frame body 6, wherein the steering post 13 includes a shaft holder 14 configured to rotatably support the steering shaft 12, and a plurality of column members 15, 16 that extend downward from the shaft holder 14 and that are fixed to the main frame body 6, and wherein the steering post 13 is detachable with respect to the main frame body 6.

According to the configuration, by providing a watchtower-like steering post 13, which supports the steering shaft 12, i.e., steering handle 11, detachable with respect to the main frame body 6 for supporting the power unit 3A and the front wheel suspension device 4, it is possible to easily consist a plurality of vehicle types that have different handle positions by sharing the main frame body 6 and by only replacing the steering post 13. In addition, by supporting the shaft holder 14 of the steering post 13 with the plurality of column members 15, 16, it is possible to suppress the weight of the steering post 13, and to appropriately support the components at the upper part of the vehicle body with the plurality of column member 15, 16, and the number of components can be reduced compared to a case in which stays and the like are provided to every components.

In the embodiment, the shaft holder 14 is configured to support the steering shaft 12 via a bearing 18 that can be automatically centered.

Accordingly, even in a shaft holder 14 supported by a plurality of column members 15, 16, it is possible to absorb the deviation of a shaft center with respect to the steering shaft 12 by a bearing 18 that can be automatically centered and to make the rotation of the steering shaft 12 satisfactory.

In the embodiment, a vehicle functional component (air cleaner box 19) is arranged in a space K surrounded with the plurality of column members 15, 16.

Accordingly, by arranging the vehicle functional components such as air cleaner box 19 and the like that requires high volume in a space K formed by the steering post 13, it is possible to cover the size of the component with efficiently using a limited components arrangement space in the saddle riding type vehicle 1.

In the embodiment, a front column member 15 that locates in front of the steering post 13 among the plurality of column members 15, 16 is arranged at a position where the front column member 15 overlaps with an axis C1 of the shaft holder 14 in a side view or a position which is rearward than the axis C1.

In this way, since the steering shaft 12 does not come inside the space K surrounded by the plurality of column members 15, 16, it is possible to secure a space in which the vehicle functional components are arranged without narrowing the space K formed by the steering post 13.

In the embodiment, each of a lower end portions 15 a, 16 a of the plurality of column members 15, 16 is fixed to the main frame body 6, the lower end portion 15 a of the front column member 15, which is located in front of the steering post 13 among the plurality of column members 15, 16, is disposed in front of a vertical line VL dropping from a center of the shaft holder 14 in a side view, and the lower end portion 16 a of the rear column member 16, which is located in rear of the steering post 13 among the plurality of column members 15, 16, is disposed in rear of the vertical line VL in the side view.

Accordingly, it is possible to support the load applied to the shaft holder 14 with the front column member 15 and the rear column member 16, that are extending so as to be broaden towards the bottom in forward and rearward, respectively, in a well-balanced manner and to achieve light weighting of the steering post 13.

Further, the present invention is not limited to the above-mentioned embodiment, and for example, the present invention may be applied to a four-wheeled vehicle including left and right front wheels and left and right rear wheels, in addition to the three-wheeled vehicle including the left and right front wheels and the single rear wheel.

While the power unit of the embodiment includes an engine as a drive source, the drive source may be an electric motor or may be a drive source including the electric motor.

The column member of the steering post is not limited to a pipe member, and may be consisted from a plate member, an angle member or various molded components (including resin-made). In addition, the number of the column member is not limited to four, at least two or more column member is acceptable. The vehicle functional components arranged in the steering post is not limited to an air cleaner box, electrical components such as battery, emission countermeasure component such as canister, and even a luggage box is acceptable as the vehicle functional components.

While preferred embodiments of the invention have been described and illustrated above, it should be understood that these are exemplary of the invention and are not to be considered as limiting. Additions, omissions, substitutions, and other modifications can be made without departing from the scope of the present invention. Accordingly, the invention is not to be considered as being limited by the foregoing description, and is only limited by the scope of the appended claims. 

What is claimed is:
 1. A frame structure of a saddle riding vehicle in which a front wheel suspension device is arranged in front of a power unit, the frame structure comprising: a main frame body configured to support the power unit and the front wheel suspension device; and a steering post configured to support a steering shaft above the main frame body, wherein the steering post includes a rotating support member configured to rotatably support the steering shaft, and a plurality of column members that extend downward from the rotating support member and that are fixed to the main frame body, wherein the steering post is detachable with respect to the main frame body, and wherein a front column member that locates in front of the steering post among the plurality of column members is arranged at a position where the front column member overlaps with an axis of the rotating support member in a side view or a position which is rearward than the axis.
 2. The frame structure of a saddle riding vehicle according to claim 1, wherein the rotating support member is configured to support the steering shaft via a bearing that can be automatically centered.
 3. The frame structure of a saddle riding vehicle according to claim 1, wherein a vehicle functional component is arranged in a space surrounded with the plurality of column members.
 4. The frame structure of a saddle riding vehicle according to claim 1, wherein each of a lower end portions of the plurality of column members are fixed to the main frame body, the lower end portion of the front column member, which is located in front of the steering post among the plurality of column members, is disposed in front of a vertical line dropping from a center of the rotating support member in a side view, and the lower end portion of a rear column member, which is located in rear of the steering post among the plurality of column members, is disposed in rear of the vertical line in the side view. 